The major objective of the proposed research is a study of the biogenesis of the protein components of mitochondria. Protein synthesis in mitochondria apparently proceeds via a mechanism similar to that occurring in the endoplasmic reticulum; i.e. mRNA's, ribosomes and tRNA's unique to mitochondria have been described. Several protein species (3-6) appear to be synthesized by mitochondria. The labeling of these proteins has been demonstrated on SDS polyacrylamide gel electrophoresis. Little is known as to the exact nature of these proteins. An attempt to characterize these will be made in this study. The possibility that mitochondria synthesize, a proteolipid present in the membrane, will be investigated. The mechanism by which mitochondria proteins, synthesized in the microsomes are transferred and subsequently integrated into the mitochondrial structure will be investigated. The role of membrane lipids in protein synthesis in isolated mitochondria as well as in the biosynthesis of the membrane will be studied in an attempt to clarify membrane biogenesis. Further studies on the induction of delta- aminolevulinic acid synthetase, the control enzyme in the overall heme biosynthetic pathway, will be conducted.